[Herd immunity against new influenza A (H1N1) in pre-vaccinated residents aged over 5 years in Beijing].
Zhonghua Jie He He Hu Xi Za Zhi
; 33(6): 403-5, 2010 Jun.
Article
en Zh
| MEDLINE
| ID: mdl-20979808
ABSTRACT
OBJECTIVE:
To explore the herd immunity against influenza A (H1N1) in pre-vaccinated residents aged over 5 years, and therefore to provide data for vaccination policies in high risk populations.METHODS:
From October to December 2009, Beijing CDC conducted a serum survey of the novel influenza A (H1N1) in the local residents, stratified in 10 age groups between 5 years to over 60 years, without H1N1 vaccination history and disease history. Hemagglutination inhibition (HI) assays were performed at Beijing CDC. Statistical significance was determined with geometric mean titer (GMT).RESULTS:
3499 serum samples were tested for HI antibody. The average level of HI antibody was 18.03, and 11.06% (387/3499) were sero-positive (HI antibody level ≥ 140). In the group aged from 5 to 19 years, the level of HI antibody and the sero-positive rate were higher (HI antibody > 18.9, sero-positive rate > 12%).CONCLUSIONS:
The antibody levels in different groups were affected by age specific morbidity, and the higher antibody level of the school-age group was correlated with higher disease intensity in this population. The data showed that the herd immunity in Beijing was under the optimal level, but influenza A (H1N1) would probably become prevalent in the short coming future.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Vacunas contra la Influenza
/
Inmunidad Colectiva
/
Gripe Humana
/
Anticuerpos Antivirales
Límite:
Adolescent
/
Adult
/
Aged
/
Child
/
Child, preschool
/
Female
/
Humans
/
Male
/
Middle aged
País/Región como asunto:
Asia
Idioma:
Zh
Revista:
Zhonghua Jie He He Hu Xi Za Zhi
Año:
2010
Tipo del documento:
Article
País de afiliación:
China